Q fever bioprosthetic aortic valve endocarditis (PVE) successfully treated with doxycycline monotherapy

Q fever is a zoonotic infection caused by Coxiella burnetii. The most common clinical manifestation of acute Q fever infection is as an atypical community-acquired pneumonia. The pulmonary findings are accompanied by extrapulmonary findings, most typically an increase in serum transaminases and splenomegaly. Because C. burnetii is difficult to culture, the diagnosis of Q fever is usually made serologically. The diagnosis of acute Q fever atypical community-acquired pneumonia is made by demonstrating a fourfold or greater increase in titer between acute and convalescent specimens or by demonstrating elevated immunoglobulin (IgM) (phase II) titers. Chronic Q fever is manifested as granulomatous hepatitis or more commonly as culture-negative endocarditis (CNE). Chronic Q fever (CNE) is a difficult diagnosis because of difficulty in culturing the organism from the blood and the vegetations with Q fever CNE are small or absent. The diagnosis of chronic Q fever CNE is based on serology. Such patients commonly have highly elevated IgM and IgG titers (phase I/II) titers. Chronic Q fever CNE may involve native or prosthetic heart valves. Q fever prosthetic valve endocarditis is rare compared with native valve Q fever endocarditis. Q fever prosthetic valve endocarditis usually requires valve replacement for cure. We present a case of chronic Q fever bioprosthetic aortic valve endocarditis that was successfully treated with doxycycline monotherapy that did not require aortic valve replacement.     

Pathologic findings after cardiac valve replacement with glutaraldehyde-fixed porcine valves.

Although approximately 20,000 glutaraldehyde-fixed porcine cardiac valve prostheses have been implanted in patients there is a lack of detailed pathologic studies of valves removed surgically or examined at necropsy. In this study, of 363 valves implanted in 311 patients, 26 valves (7 percent) from 23 patients (7 percent) were examined morphologically. Of the 23 patients, 14 died intraoperatively or less than 1 month after valve replacement—3 from coronary artery disease, 4 from hemorrhagic myocardial necrosis, 2 from postoperative hemorrhage, 2 from pulmonary disease and 1 from phycomycosis of the prosthesis; in 2 patients no anatomic cause of death was found. Six patients died 1 to 9 months after valve replacement—one from prosthetic thrombotic stenosis, one from prosthetic endocarditis and four from causes unrelated to their prosthesis. Three patients underwent surgical excision of a malfunctioning valve 12 to 31 months after implantation; incompetence was due to infective endocarditis in two patients and to a torn cusp in one.     

Cardiac valves in patients with Q fever endocarditis: microbiological,molecular, and histologic studies

The pathologic features of Q fever endocarditis, which is caused by Coxiella burnetii, were histologically evaluated in cardiac valves from 28 patients. We used quantitative image analysis to compare valvular fibrosis, calcifications, vegetations, inflammation, and vascularization due to Q fever endocarditis with that due to non-Q fever endocarditis and valvular degeneration. We also studied the presence of C. burnetii in valves by immunohistochemical analysis, culture, and polymerase chain reaction (PCR). Histologically, Q fever endocarditis was characterized by significant fibrosis and calcifications, slight inflammation and vascularization, and small or absent vegetations. Despite antibiotic treatment, non-statistically significant variations at the histologic level were observed. These pathologic features could be confused with noninfectious valvular degenerative damage. We found that the detection of C. burnetii in cardiac valves by immunohistochemical analysis, culture, and PCR decreased significantly only after 1 year of antibiotic treatment, which emphasizes the long persistence of this organism in valve tissues. Pathologic and immunohistochemical analyses may contribute to the diagnosis of Q fever endocarditis.     

Comparative clinical experience with porcine bioprosthetic and St. Jude valve replacement

From 1976 to 1984, 656 patients underwent aortic, mitral, or double valve replacement with a Hancock or Carpentier-Edwards porcine bioprosthesis (POR; n = 293) or with a St. Jude bileaflet valve (SJ; n = 363). Recipients of the St. Jude valve were of more advanced NYHA class preoperatively, required smaller prosthetic sizes, and more often had associated coronary artery disease necessitating bypass grafting (p less than .05). Despite these differences, POR and SJ recipients demonstrated similar 30-day mortality (7.5 vs 10.2 percent), five-year freedom from embolism (92 +/- 2 percent vs 92 +/- 2 percent), freedom from all valve-related complications (79 +/- 3 percent vs 79 +/- 4 percent), and survival (72 +/- 3 percent vs 71 +/- 3 percent) (p = NS). Structural failures occurred exclusively in POR recipients (3.0-4.5 percent/pt-yr after four years), and endocarditis was more common (1.0 vs 0.5 percent/pt-yr); as a result, the reoperation rate was three times higher in POR than SJ recipients (1.4 vs 0.46 percent/pt-yr, p less than .05). Warfarin-related bleeding (2.5 percent/pt-yr) was the most common complication in SJ recipients, but occurred equally frequently in POR recipients requiring anticoagulation; seven (44 percent) of 16 valve-related late deaths were warfarin-related. In properly anticoagulated patients, the thromboembolic rate was low (2.0 percent and 1.1 percent/pt-yr, POR and SJ); this rate increased significantly in SJ recipients receiving antiplatelet drugs alone (4.2 percent/pt-yr; n = 16) or no anticoagulant or antiplatelet therapy (26.4 percent/pt-yr; n = 18) (p less than .05), but increased only slightly in POR recipients (to 1.5 percent/pt-yr, n = 108, and 2.0 percent/pt-yr, n = 63, respectively). Postoperatively, NYHA class 1 was more often achieved in SJ than POR recipients (60 vs 39 percent, p less than .05), perhaps because of the better hemodynamic performance of the SJ valve. Thus, despite differences in patient selection and the nature of complications observed with each prosthetic type, porcine and St. Jude valves provide similar early and late survival, frequency of embolism, total complication rate, and freedom from valve-related morbidity and mortality after five years of follow-up. Limited durability, susceptibility to infection, and inferior hemodynamics remain drawbacks to use of the porcine bioprosthesis. The necessity for warfarin anticoagulation and the frequency of resultant bleeding complications are the major shortcomings of the St. Jude valve.(ABSTRACT TRUNCATED AT 400 WORDS)     

Pregnancy in 20 patients with bioprosthetic valve replacement

We studied twenty women who became pregnant after porcine bioprosthetic valve replacement. Six patients had aortic valve, seven mitral, and seven aortic plus mitral valve replacement. All women were treated with aspirin (1 g daily or 500 mg every 48 hours) during pregnancy, delivery, and the postdelivery period. Thirteen patients experienced atrial fibrillation. There were 27 pregnancies with three ending in abortion. Twenty five normal babies were delivered. There was no maternal mortality or morbidity from thromboembolism or hemorrhage. Comparison of the pregnancy course of these women and the general population shows no difference with respect to fetal or maternal morbidity and mortality. Pregnant women with bioprosthetic valve replacement treated with aspirin had normal pregnancies without the risk of thromboembolism. Fetal and perinatal morbidity and mortality was also within normal limits.     

Native valve endocarditis due to coagulase-negative staphylococci. Clinical and microbiologic features

Twenty-one patients with native valve endocarditis caused by coagulase-negative staphylococci were studied; 14 had pre-existing valvular or congenital heart disease. Although commonly subacute in presentation, complications of endocarditis were frequent: arterial emboli in five patients, new electrocardiographic conduction system abnormalities in nine, congestive heart failure in eight, annular or myocardial abscesses in five, and disruption of valve leaflets in three. Cures were achieved in 10 of 12 patients treated medically and seven of nine treated surgically. In microbiologic studies of 16 coagulase-negative staphylococci from patients with endocarditis, only eight were identified as Staphylococcus epidermidis. All isolates were susceptible to vancomycin. Antibiotic resistance (methicillin, four isolates; gentamicin, two isolates; rifampin, one isolate) was usually associated with nosocomial acquisition of endocarditis. Rather than representing contamination, coagulase-negative staphylococci in blood cultures may indicate life-threatening endocarditis. However, with careful attention to the selection of antibiotics for therapy and to the occurrence of heart failure due to intracardiac complications, treatment of this form of endocarditis is frequently successful. Organisms must always be tested for cryptic resistance to beta-lactam antibiotics. Valve replacement may be required frequently.     

60～70岁患者主动脉机械瓣与生物瓣中期疗效对比

目的 对比分析60~70岁患者行主动脉瓣机械瓣置换与生物瓣置换术后生存率、术后瓣膜并发症情况及再次手术率的差异。 方法 回顾性分析2005年1月至2015年12月在解放军总医院第一医学中心心血管外科行主动脉瓣机械瓣置换的64例60~70岁患者与同年龄段的147例行主动脉瓣生物瓣置换的患者的病例资料。根据术前基线资料,利用倾向性评分匹配方法对患者分组。分组后比较两组患者瓣膜置换术后的生存率、瓣膜相关病死率、瓣膜相关并发症发生率及再次手术率的差异。 结果 倾向性评分匹配后,机械瓣组与生物瓣组术后6年,两组患者的生存率及瓣膜相关病死率无统计学差异(P=0.160,P=1.000)。机械瓣组术后并发症包括机械瓣非结构性功能异常1例(2.1%),栓塞1例(2.1%)、出血1例(2.1%),生物瓣组术后并发症包括瓣膜血栓1例(2.1%)、栓塞4例(8.2%)。总体的并发症发生率两组无统计学差异(P=0.321)。生物瓣组6年内再次手术1例(2.1%),机械瓣组未发生再次手术,组间比较无统计学差异(P=1.000)。 结论 我中心60至70岁年龄段患者行主动脉瓣机械瓣或生物瓣置换术后6年的生存率、瓣膜相关病死率、并发症发生率及再次手术率无明显差异。     

Candida endocarditis treated with a combination of antifungal chemotherapy and aortic valve replacement.

A case of Candida albicans endocarditis is described in which treatment with 5-fluorocytosine was started after aortic valve replacement, but relapse followed discontinuance of treatment. At a second operation the aortic valve was replaced under 5-fluorocytosine cover and treatment was continued with both 5-fluorocytosine and amphotericin-B. No resistance to 5-fluorocytosine developed, and the candida infection was eradicated. The patient is well 22 months after his operation.     

Prosthetic valve endocarditis: Clinicopathologic analysis of 22 necropsy patients with comparison of observations in 74 necropsy patients with active infective endocarditis involving natural left-sided cardiac valves

Clinical and morphologic features are described in 22 necropsy patients with endocarditis involving rigid-framed prosthetic valves: aortic in 15 patients and mitral in 7. The interval from valve replacement to onset of symptoms of prosthetic valve endocarditis was less than 2 months in 8 patients and longer than 2 months in 14 patients. The most frequent infecting organism was the Staphylococcus (13 patients). In each of the 22 patients the infection was located behind the site of attachment of the prosthesis to the valve ring, and the infection spread to adjacent structures in 13 patients, 11 of whom had aortic prostheses. Prosthetic detachment causing severe regurgitation occurred in 12 ot the 15 patients with an infected aortic valve prosthesis, and in 2 of the 7 with an infected mitral valve prosthesis. Prosthetic obstruction by vegetative material occurred in 5 of 7 patients with prosthetic mitral infection and in only 1 of 15 with prosthetic aortic infection. High degrees of conduction defects developed in seven patients with aortic prosthetic valve endocarditis: complete heart block in five, and complete left bundle branch block in two.Comparison of observations in the 22 patients with prosthetic valve endocarditis with those in 74 patients with active infective endocarditis involving natural left-sided cardiac valves revealed significant (P < 0.05) differences in the percent with ring abscess, hemodynamic consequences of the endocarditis (valve stenosis), frequency of Staphylococcus as the causative organism and percent with complete heart block or left bundle branch block. No significant differences were observed between the two groups when comparing age, sex, type of underlying valve disease or frequency of organ infarcts or splenomegaly.     

Candida endocarditis treated with a combination of antifungal chemotherapy and aortic valve replacement.

A case of Candida albicans endocarditis is described in which treatment with 5-fluorocytosine was started after aortic valve replacement, but relapse followed discontinuance of treatment. At a second operation the aortic valve was replaced under 5-fluorocytosine cover and treatment was continued with both 5-fluorocytosine and amphotericin-B. No resistance to 5-fluorocytosine developed, and the candida infection was eradicated. The patient is well 22 months after his operation.     

Doppler echocardiographic study of porcine bioprosthetic heart valves in the aortic valve position in patients without evidence of cardiac dysfunction

To study the natural history of the hemodynamic performance of bioprosthetic heart valves, Doppler echocardiograms were recorded in a group of clinically stable patients at 2 and 5 years after replacement of native aortic valves with bioprosthetic valves. Eighteen patients completed a 2-year and 26 patients a 5-year follow-up examination. The effective orifice areas of identical models of bioprosthetic valves (Hancock II) were determined in vitro in a left-sided heart pulse duplicator system. In vivo Doppler-derived effective orifice areas were compared with the in vitro measurements for the same valve size. At both the 2- and 5-year follow-up examinations, the Doppler-derived effective orifice area was significantly less than the in vitro area (p less than 0.0001 at each interval). Ten of 16 valves evaluated serially decreased greater than 0.20 cm2 in the Doppler-derived effective orifice area between studies. The mean decrease in effective orifice area in valves evaluated serially was 0.25 +/- 0.29 cm2 (p less than 0.005). The peak transaortic gradient increased from 21 +/- 6 to 27 +/- 8 mm Hg (p less than 0.01). The mean transaortic gradient increased from 12 +/- 4 to 15 +/- 7 mm Hg (p less than 0.05). It is concluded that serial Doppler echocardiographic studies demonstrate a deterioration in the hemodynamic performance of bioprosthetic valves over time in patients with no symptoms or signs of valvular dysfunction and that Doppler echocardiography may be useful for identifying subclinical bioprosthetic valvular dysfunction.     

Fatal bacterial endocarditis following aortic valve replacement in a patient being treated with methotrexate.

A 41-year-old man being treated with methotrexate for psoriasis underwent aortic valve replacement. He subsequently developed fulminating bacterial endocarditis. Bacterial endocarditis occurs in 1-2% of cases after prosthetic valve replacement and has a high mortality. The long-term use of methotrexate and similar drugs is increasing in conditions such as psoriasis, rheumatoid arthritis and inflammatory bowel disease. Thus, more patients undergoing heart valve surgery will be taking these preparations for coexisting disease. As methotrexate increases the risk of infection, its perioperative use in these patients requires further evaluation.     

Sutureless aortic valve replacement in high-risk patients with active infective endocarditis

BackgroundSurgical aortic valve replacement remains the gold standard of treatment in patients with active infective endocarditis. Such procedures tend to carry a significantly higher operative risk when compared to the conventional aortic valve replacement for a non-infective aortic valve disease. Sutureless aortic valve replacement (SU-AVR) has been introduced into cardiac surgery to allow for a simpler implementation of minimally invasive procedures. Although SU-AVR in several extended indications has proven to be successful, the data on the implementation of SU-AVR in patients with infective aortic valve endocarditis remain scarce. The aim of the study was to examine the feasibility of SU-AVR in high-risk patients with active infective aortic valve endocarditis.MethodsBetween December 2019 and March 2022, a total of 151 consecutive patients underwent a SU-AVR for various indications at our institution. Of those, in 13 consecutive high-risk patients SU-AVR was indicated because of infective aortic valve endocarditis. In all cases Perceval S aortic valve prosthesis (Corcym, Saluggia, Italy) was used and the implantation has been performed with Snugger-method.ResultsThe mean age of the patients at operation was 74.05±11.6 years. Eight of the patients suffered from prosthesis endocarditis while the other five patients presented with the endocarditis of the native aortic valve. All patients suffered from multiple comorbidities, as reflected by a mean logistic EuroSCORE of 47.9%±23.1% and EuroSCORE II of 28.7%±22.0%. In 8 patients (61.5%) a concomitant procedure was necessary. Also 8 patients (61.5%) underwent a redo procedure. Bypass- and cross-clamp (CC) times were 89.8±33.6 and 59.1±27.8 minutes, respectively. We observed no paravalvular leakage and no cases of left-ventricular outflow tract obstruction. Postoperative mean gradients after SU-AVR implantation were 8.1±4.8 mmHg.ConclusionsSU-AVR in patients presenting with active infective endocarditis is a safe and feasible surgical alternative to the conventional operation. Clearly, this operative approach should be considered particularly for high-risk patients in whom successful operative outcomes are determined by a reduction in bypass and CC time. SU-AVR provides excellent hemodynamic performance with a low risk of paravalvular leakage and low transvalvular gradients, whilst simplifying the surgical procedure.     

Huge left atrial thrombus and valve degeneration in a patient with a bioprosthetic, porcine, mitral valve

A 43 year old man with a Hancock porcine bioprosthetic valve in the mitral position developed a huge thrombus filling the entire left atrium and chronic degeneration of the bioprosthetic mitral valve. The effective valve orifice was less than 2 mm. These severe findings leading to the patient's death remained undetected while he was alive. This case illustrates the great need for a serial phonoechocardiographic studies in all patients with prosthetic valves.     

Structure and classification of cuspal tears and perforations in porcine bioprosthetic cardiac valves implanted in patients

Morphologic studies were made of cuspal tears and perforations in 16 porcine valve bioprostheses that had been implanted in 14 patients (9 male and 5 female) ranging in age from 2 to 65 years. Eleven bioprostheses had been in the mitral position for 30 to 123 months, four in the aortic position for 15 to 40 months and one in a valved pulmonary conduit for 96 months. The cuspal lesions were classified into four types. Type I lesions, which involved the free edges of the cusps, were the most common of all lesions and occurred with equal frequency in mitral and aortic bioprostheses. Regardless of position of implantation, type I lesions were more frequent in the right coronary cusp than in the other cusps. Ultrastructural study showed that these lesions develop as consequences of breakdown of collagen at the free edges of the cusps, usually near the commissures. Type II lesions consisted of linear perforations that extended along the basal regions of the cusps, forming an arc parallel to the sewing ring. These lesions were uncommon and resulted from separation of bundles of collagen. Type III lesions, which were large, round or oval perforations that occupied central regions of the cusps, were more common in aortic than in mitral bioprostheses. They were characterized by marked destruction of cuspal tissue and were most frequently associated with infection. Type IV lesions were small pinhole-like perforations; they usually were multiple, localized in central regions of the cusps and associated with calcific deposits. Type IV lesions were more common in mitral than in aortic bioprostheses. Regardless of position, they were more frequent in the left and noncoronary cusps than in the right coronary cusp (which may be protected by its muscle shelf against this type of perforation). It is concluded that cuspal tears and perforations develop in implanted bioprostheses as consequences of structural failure of connective tissue components.